[MITgcm-devel] more seaice

[Dimitris Menemenlis]

> The way I understand this is that the stress on the ice is an average over 
> ocean stress and ice stress ( the statement before FORCEX(I,J,bi,bj) = ...), 
> whereas the stress over the ocean is just the ocean stress not weighted at 
> all. I find this a little inconsistent if not wrong. I would think that these
>  terms should be treated separately, with only the ice stress driving the
> ice, right?

Martin, yes it is inconsistent.  As Jinlun mentioned in an earlier message, the
original formulation for ocean stress, the one marked by CPP flag
SEAICE_ORIGINAL_BAD_ICE_STRESS in ostres.F caused model instabilities.  As a
temporary fix, the presence of ice is ignored in the computation of ocean
surface stress, variables WINDX and WINDY.

Regarding ocean stress at bottom of ice, variables FORCEX and FORCEY, my 
understanding is that dynsolver assumes that thin ice covers the open ocean 
everywhere, hence the weighted sum of ice-covered and ice-free components in the 
computation of FORCEX and FORCEY.  But I do not know whether and why this 
thin-ice assumption is required nor what would be impact of setting the URT/VRT 
mask to zero where AREA=0.

Dimitris